/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#ifndef NET_INSTAWEB_HTTP_PUBLIC_HTTP_VALUE_WRITER_H_
#define NET_INSTAWEB_HTTP_PUBLIC_HTTP_VALUE_WRITER_H_

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/string_util.h"

namespace net_instaweb {

class HTTPCache;
class HTTPValue;
class MessageHandler;
class ResponseHeaders;

// Wrappper for buffering an HTTPValue. HTTPValueWriter ensures that an
// HTTPValue which cannot be eventually cached is not buffered.
class HTTPValueWriter {
 public:
  HTTPValueWriter(HTTPValue* value, HTTPCache* cache)
      : value_(value), cache_(cache), has_buffered_(true) {}

  void SetHeaders(ResponseHeaders* headers);

  bool Write(const StringPiece& str, MessageHandler* handler);

  bool has_buffered() const { return has_buffered_; }

  // Checks if the http_value should be buffered or not depending on whether we
  // can eventually cache it. It also clears the http_value if it can not be
  // buffered. Note that this only checks the size constraints, not cache
  // headers.
  bool CheckCanCacheElseClear(ResponseHeaders* headers);

  // Checks if we can write the string to the HttpValue without going over
  // limits.
  bool CanCacheContent(const StringPiece& str) const;

 private:
  HTTPValue* value_;
  HTTPCache* cache_;
  bool has_buffered_;
  DISALLOW_COPY_AND_ASSIGN(HTTPValueWriter);
};

}  // namespace net_instaweb
#endif  // NET_INSTAWEB_HTTP_PUBLIC_HTTP_VALUE_WRITER_H_
